Mitsubishi FREQROL-SF Troubleshooting Manual page 39

(15) Alarm No.33(OV)
[The voltage in the converter circuit is
checked and if it exceeds 400 V, this alarm
occurs.)
Item Cause
The input power voltage
waveform is abnormal.
1
The input power imped-
2
An instantaneous power
failure occurs in the
input voltage or the
3
voltage drops when the
motor decelerates.
The printed circuit
board SF-CA card is
4
defective.
The main circuit unit
is defective.
5
Check
alarm No.24, No.25, and
No.32, check the waveform.
alarm No.24/NoW25/No.32,
check the input power.
alarm No.lO(LJV), check the
input power.
a new one and check that the
equipment correctly works.
transistor module by refer-
Remedy
No.32.
cable between the input
power supply and the ampli-
fier.
Improve other components
which generate distorted
waves by installing surge
killers and so forth.
No.32.
with that whose impedance
is low.
cable connections between
the input power and ampli-
fier.
instantaneous power failure
or voltage drop and improve
the power condition.
board SF-CA card with a
new one.
(See Section 2.4.4.)
circuit unit with a new
one.
(Note) See Section 2.7.